Land mine overpass tread design

ABSTRACT

A land mine pressure fuse avoidance system has a base. A tread on the base contacts the ground around a land mine and independently distributes pressures around the ground. The tread has plural independent closed cell foam rubber elements. Each element is separated from adjacent elements for independently supporting only a portion of a load on the base, while other similarly independent elements support remaining portion of the load. The base is a cylindrical tire, a continuous track, a shoe sole attachment or a robotic foot, and the tread is conformed to and extends outward from the base. The independent elements of the tread are made of closed cell foam rubber formed as a tread on the base with notches between adjacent elements of the tread. Notches extend longitudinally along the tread, and notches extend across the tread, forming block shaped elements extending from the base. The notches extend into the tread for distances greater than heights above ground of clutter and of partially buried mines or fuses. In one form the tread has independent radially extending elements constructed of closed cell foam.

BACKGROUND OF THE INVENTION

Land mines are dangerous and claim the lives of thousands of soldiers orinnocent civilians every year. Most land mines are detonated by apressure-activated fuse. The pressure required to activate those fusesrange from ounces to many pounds. Anti-personnel mines typically requireone or so pounds to detonate. The overwhelming majority of anti-tankmines require several pounds of pressure to detonate.

A large worldwide community is dedicated to ridding the world of futureand already emplaced land mines. Various governments and humanitarianefforts are developing land mine detection systems to pinpoint thelocations of land mines so personnel and equipment can avoid the minesthat might detonate and cause damage. All efforts including theday-to-day civilian activities in mined countries could benefit frommine-overpass-capabilities.

The countermine community typically assumes that low ground pressurevehicles automatically create a mine overpass capability. Low groundpressure vehicles could be lightweight vehicles with very wide air-filedtires, or lightweight vehicles with wide flat tracks like a lightweightbulldozer, or a hovercraft.

Low ground pressure does not automatically mean low mine pressure. Lowmine fusing mechanism pressure is the problem to be solved. Forpressure-fused mines, pressure on the mine's trip-mechanism causes it todetonate. A low ground pressure vehicle with a large contact patch onflat ground could have an extremely low ground pressure but a mine-fusepressure that is half or all of its weight.

When a large stone, for example, is placed over a mine an entiresoft-tire may be lifted from the ground so that a quarter of a vehicle'sweight bears on the stone. When the tire is lifted, the stone transmitsthat entire force from one tire to the mine fuse.

Assume for a moment that a human weighs 200 pounds and has two feet inboots with extremely stiff soled shoes that are perfectly flat with 50square inches that touch the ground. This human's pressure on the groundis about 4 pounds per square inch (200/50). If on the other hand thehuman steps on a partially buried mine with one foot as he or she iswalking, the pressure on that mine's trip-mechanism could be as much as200 pounds.

Needs exist for improved ground contact apparatus and methods to avoidtriggering mines while moving in mined areas.

SUMMARY OF THE INVENTION

A land mine pressure fuse avoidance system has a base. A tread on thebase contacts the ground around a land mine and independentlydistributes pressures around the ground. The tread has pluralindependent closed cell foam rubber elements. Each element is separatedfrom adjacent elements for independently supporting only a portion of aload on the base, while other similarly independent elements supportremaining portion of the load. The base is a cylindrical tire, acontinuous track, a shoe sole attachment or a robotic foot, and thetread is conformed to and extends outward from the base. The independentelements of the tread are made of closed cell foam rubber formed as atread on the base with notches between adjacent elements of the tread.Notches extend longitudinally along the tread, and notches extend acrossthe tread, forming block shaped elements extending from the base. Thenotches extend into the tread for distances greater than heights aboveground of clutter and of partially buried mines or fuses. In one formthe tread has independent radially extending elements constructed ofclosed cell foam.

An improvement is to make a very soft tread to encourage the mine orcovering clutter to move into the tread and let some part of the weightflow around the mine through the tread and onto the ground. Minimizingmine-fuse pressure is helped by letting the tread material flow aroundthe mine's fuse to make contact with the perimeter of the mine and theground.

This invention provides notched, thick, closed cell foam rubber treadfor any part of a land mine overpass platform that contacts the ground.Land mine overpass platforms, might be humans, manned-vehicles, unmannedvehicles, or legged robots with tires, tracks or feet that contact theground.

A conceptual land mine detection system includes a remotely controlledcart and a land mine detection sensor. Notched closed cell foam rubbertires or tread material is used to minimize land mine detonations whilepassing over land mines.

A closed cell foam rubber notched tire rests on the ground. Sidewallparts of the closed-cell foam rubber are not notched and stretch-fitover a rim. Many notches are cut into the foam rubber tread. The notchesextend from the perimeter of the tire to some depth that is greater thanmost clutter objects and mines that the tire must pass over withoutdetonating. The notches are an important part of the invention, as theyprevent nearby notch-separated foam elements from exerting pressure onthe mine's fusing mechanism. Equally important is the down-track contactlength that the tire makes with the ground. It is important that theclosed-cell foam rubber tire material be of a resiliency to permit amaximum contact area with the ground while providing adequate stabilityfor the platform. The resiliency of the foam will vary depending on theweight of the platform and the speed at which it must maneuver.

When encountering a partially buried mine, the invention sits over andconforms to the mine that is buried in the ground. The closed cell foamretracts to allow the mine to move into the foam. The molding around themine lets the foam rubber elements touch the ground and minimizespressure on the land mine's fusing mechanism. Many parts of the treadtouch the ground and therefore minimize the pressure on the land mine'sfuse by transferring a maximum of the vehicle's weight to the ground. Ifthe notches were not present, more of the tread would be suspended abovethe ground and more pressure would be dangerously on the mine's fusingmechanism.

When a completely buried mine is covered with a clutter object, such asa rock, the invention conforms to the clutter object by compressing andcreates more uniform ground pressure and therefore minimum pressure onthe clutter object. Because the clutter object is over the mine,minimizing the pressure on the clutter object also minimizes thepressure on the mine's fusing mechanism.

A human wearing a boot fastens the invention using straps with Velcro orbuckles. A more rigid backing is used for the foam rubber tread. Therigid backing is approximately 1-centimeter thick durable plastic and isfastened to the foam rubber using adhesive. The notched foam rubbercompresses over a mine to give maximum contact with the ground.

The invention is also used for a tracked vehicle. The tracked vehiclechassis is carried by closed cell foam treads that are notched. Thetracks are driven by drive wheels and rollers. The notched foam rubbertread conforms around the mine to give maximum contact with the ground.Tracked vehicles give very low ground pressure, because the contact withthe ground is very long with an infinite radius relative to round tires.Tracked vehicles with hard tread, however translate tremendous weight tothe mines fusing mechanism. This invention, with its soft, notchedtread, minimizes the pressure exerted on the mines fusing mechanism.

The invention is also used on robots with legs rather than wheels ortracks. The robot may have many legs like an insect. The body carriespower and a motor drive mechanism. Legs are attached to the body. Theinvention is attached to the legs and has feet with flexible bases andclosed cell foam rubber treads with notches. The notches conform aroundpartially buried mines that are in the ground. The foam rubber contactwith the ground is maximized, therefore minimizing the pressure on theland mine's fusing mechanism.

An improvement makes a very soft sole to encourage the mine to move intothe sole and let some part of the weight flow around the mine and ontothe ground.

This invention proposes using notched, thick, closed cell foam rubbertread for any part of a landmine overpass platform that contacts theground. Landmine overpass platforms might be humans, manned vehicles,unmanned vehicles, or legged robots that contact the ground.

These and further and other objects and features of the invention areapparent in the disclosure, which includes the above and ongoing writtenspecification, with the claims and the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a land mine removing or destroying vehicle using notchedfoam rubber wheels.

FIG. 2A schematically shows a side view of a notched foam rubber tire.

FIG. 2B shows a notched foam rubber tire footprint.

FIG. 3 shows pressure distribution in a side elevation of a notched foamrubber tire.

FIG. 4 shows a buried mine covered by clutter and pressure distributionin a side elevation cross-section of a notched foam rubber tread.

FIG. 5 is a side elevation of a boot with a strapped-on notched foamrubber boot base.

FIG. 6 shows a side elevation in cross section of a vehicle continuoustrack with a notched foam rubber tread.

FIG. 7 shows notched foam rubber tread feet on a mechanical robot.

FIG. 8A is a partial cross-section of air-filled rubber protrusions froman air-filled tire.

FIG. 8B shows the tire tread footprint of the tire of FIG. 8.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIG. 1, a land mine detection vehicle system is generallyindicated by the numeral 1. The system includes a remotely controlledcart 3 and a land mine detection sensor 5. The vehicle 1 is supported onnotched closed cell foam rubber tire 7 and tread material used tominimize land mine detonations while passing over land mines.

Referring to FIG. 2A, a notched closed cell foam rubber tire rests onthe ground 17. A part 11 of the closed-cell foam rubber is not notchedand stretch-fits over a rim 21. Many notches 13 are cut into the foamrubber. The notches 13 extend from the perimeter 23 of the tire 25 tosome depth that is greater than the height of most clutter objects andmines that it must pass over without detonating a mine. The notches 13are an important part of the invention, as they prevent nearby notchedfoam elements from exerting pressure on the mine's fusing mechanism.Equally important is the down-track contact length 15 that the tire 25makes with the ground 17.

Referring to FIG. 2B, a notched foam rubber tire footprint 19 has tiretread width 31 and tire footprint length 33.

It is important that the closed-cell foam rubber tire material be of aresiliency to permit a maximum contact area with the ground whileproviding adequate stability for the platform. The resiliency of thefoam will vary depending on the weight of the platform and the speed atwhich it must maneuver.

Referring to FIG. 3, when the present invention encounters a partiallyburied mine 41, the invention sits over and conforms to the mine 41 thatis buried in the ground 43. The closed cell foam 45 retracts to allowthe mine 41 to move into the foam. The molding around the mine 41 letsthe foam rubber elements touch the ground 47 and minimizes pressure onthe land mine's fusing mechanism. Many parts of the tread touch theground and therefore minimize the pressure on the land mine's fuse bytransferring a maximum of the vehicle's weight to the ground 43. If thenotches were not present, more of the tread would be suspended above theground, and more pressure would be dangerously on the mine's fusingmechanism.

Referring to FIG. 4, when a completely buried mine 53 is covered with aclutter object 51, such as a rock, the invention conforms to the clutterobject 51 by compressing 55 and creates more uniform ground pressure andtherefore minimum pressure on the clutter object 51. Because the clutterobject is over the mine 53, minimizing the pressure on the clutterobject 51 also minimizes the pressure on the mine's fusing mechanism.

Referring to FIG. 5, a human wearing a boot 65 fastens to the inventionusing straps 67 with Velcro or buckles. A more rigid backing 69 is usedfor the foam rubber tread 71. The rigid backing 69 is approximately1-centimeter thick durable plastic and is fastened to the foam rubberusing adhesive. The notched foam rubber compresses 61 over the mine 73to give maximum contact with the ground 63.

Referring to FIG. 6, the invention is also used for a tracked vehicle81. A mine 83 is partially buried in the ground 85. The tracked vehiclechassis 87 is carried by closed cell foam treads 89 that are notched 91.Drive wheels and rollers 95 drive the tracks. The notched foam rubbertread conforms 97 around the mine 83 to give maximum contact 99 with theground 85. Tracked vehicles give very low ground pressure because thecontact with the ground is very long with an infinite radius relative tothe round tires. Tracked vehicles with hard tread, however translatetremendous weight to a mines' fusing mechanism. This invention, with itssoft, notched tread, minimizes the pressure exerted on the mines fusingmechanism.

Referring to FIG. 7, the invention 107 is also used on robots 101 withlegs 103 rather than wheels or tracks. The robot 101 may have many legs103 like an insect. The body 105 carries power and a motor drivemechanism. Legs 103 are attached to the body 105. The invention 107 isattached to the legs 103 and has notches 109. These notches 109 conform111 around a partially buried mine 113 that is in the ground 115. Thefoam rubber contact with the ground is maximized 117, thereforeminimizing the pressure on the land mine's fusing mechanism.

The above descriptions and FIGS. 1–7 show foam-filled notched treads.

FIG. 8A adds an air-filled tire with air-filled treads. The treads arelike the fingers on a surgical rubber glove after it has been filledwith air, except they are closer together. Both devices (foam or airversion) will give adequately low ground pressure. The air-filled tiremay allow for lower manufacturing costs, lower weight and longer lifebetween failures.

FIGS. 8A and 8B show a soft pneumatic tire 121 with closely laterallyadjacent air-filled fingers 123 with cylindrical shapes 125 and taperedends 127, which provide a large weight-distributing footprint 129 uponthe ground 131.

Similar pneumatic bases and air-filled fingers for treads may be used asshow attachments or as ground-engaging parts for tracked vehicles orrobots.

Referring to FIG. 8B, an air-filled tire footprint has tire tread width133 and tire footprint length 135. The two-dimensional contact area 137represents the down-track contact length that the tire makes with theground.

While the invention has been described with reference to specificembodiments, modifications and variations of the invention may beconstructed without departing from the scope of the invention, which isdefined in the following claims.

1. A land mine pressure fuse avoidance system comprising a base, a tread on the base for contacting ground around a land mine and for distributing pressures around the ground, the tread comprising plural independent closed cell foam rubber elements, each element spaced from adjacent elements for independently supporting only a portion of a load on the base while other independent elements together support remaining portions of the load, wherein the base is a cylindrical tire, continuous track, or shoe sole attachment and the tread is conformed to and extends outward from the base, wherein each independent element is a closed cell foam rubber cylindrically formed as a tread on the base with notches between adjacent elements of the tread, wherein the notches are formed across the base and the closed cell foam rubber elements extend across the base.
 2. The apparatus of claim 1, wherein the base has side walls stretched into rims of a vehicle and wherein the base is filled with foam or air.
 3. A land mine pressure fuse avoidance system comprising a base, a tread on the base for contacting ground around a land mine and for distributing pressures around the ground, the tread comprising plural independent closed cell foam rubber elements each element separated from adjacent elements, an independent support formed by each of the elements for independently supporting only a portion of a load on the base while other similarly independent elements together support remaining portions of the load, wherein the base is a cylindrical tire, continuous track, or shoe sole attachment and the tread is conformed to and extends outward from the base, wherein each independent element is a closed cell foam rubber cylindrically formed as a tread on the base with notches between adjacent elements of the tread, and wherein the notches extend into the tread for distances greater than heights above ground of clutter or of partially buried mines or fuses.
 4. The apparatus of claim 3, wherein the base is filled with foam or air and wherein the independent elements radially extend therefrom.
 5. The apparatus of claim 3, wherein the base is a continuous track and the plural independent closed cell foam rubber elements are spaced laterally and longitudinally from next adjacent elements.
 6. The apparatus of claim 3, wherein the notches extend longitudinally along the tread separating the elements as longitudinal elements.
 7. The apparatus of claim 6, wherein the notches extend across the tread, forming block shaped elements extending from the base.
 8. A land mine pressure fuse avoidance system comprising a base, a tread on the base for contacting ground around a land mine and for distributing pressures around the ground, the tread comprising plural independent closed cell foam rubber elements, each element spaced from adjacent elements for independently supporting only a portion of a load on the base while other independent elements together support remaining portions of the load, wherein the base is a vehicle track and wherein the independent closed cell foam elements are separated from laterally and longitudinally adjacent elements.
 9. A land mine pressure fuse avoidance system comprising a base, a tread on the base for contacting ground around a land mine and for distributing pressures around the ground, the tread comprising plural independent closed cell foam rubber elements, each element spaced from adjacent elements for independently supporting only a portion of a load on the base while other independent elements together support remaining portions of the load, wherein the base is a vehicle track and wherein the independent closed cell foam elements are separated from longitudinally adjacent elements.
 10. A land mine pressure fuse avoidance system comprising a base, a tread on the base for contacting ground around a land mine and for distributing pressures around the ground, the tread comprising plural independent closed cell foam rubber elements, each element spaced from adjacent elements for independently supporting only a portion of a load on the base while other independent elements together support remaining portions of the load, wherein the base is a vehicle track and wherein the independent closed cell foam elements are separated from laterally adjacent elements.
 11. A method of avoiding triggering of pressure operated land mines comprising providing a base, providing a tread on the base for contacting ground around a land mine and independently distributing pressures around the ground, wherein the providing a tread comprises providing plural independent closed cell foam rubber elements each element separated from adjacent elements, independently supporting only a portion of a load on the base with some of the elements, while simultaneously supporting remaining portions of the load with other independent elements acting together.
 12. A method of avoiding triggering of pressure operated land mines comprising providing a base, providing a tread on the base for contacting ground around a land mine and independently distributing pressures around the ground, wherein the providing a tread comprises providing plural independent closed cell foam rubber elements each element separated from adjacent elements, independently supporting only a portion of a load on the base with some of the elements, while simultaneously supporting remaining portions of the load with other independent elements acting together, wherein the providing the base comprises providing a cylindrical tire, a continuous track, or a shoe sole attachment and providing the tread comprises conforming the elements to the base and extending the elements outward from the base.
 13. The method of claim 12, wherein the providing the notches further comprises extending the notches into the tread for distances greater than heights above ground of clutter or of partially buried mines or fuses.
 14. The method of claim 12, wherein the providing the tread comprises providing a closed cell foam rubber cylinder formed as a tread on the base with notches between adjacent elements of the tread.
 15. The method of claim 14, wherein the providing notches comprises forming the notches across the base and the providing the closed cell foam rubber elements comprises extending the elements across the base.
 16. The method of claim 14, wherein the providing the notches comprises extending the notches longitudinally along the tread and separating the elements as longitudinal elements.
 17. The method of claim 16, wherein the providing the notches further comprises extending the notches across the tread and forming block shaped elements extending from the base.
 18. A method of avoiding triggering of pressure operated land mines comprising providing a base, providing a tread on the base for contacting ground around a land mine and independently distributing pressures around the ground, wherein the providing a tread comprises providing plural independent closed cell foam rubber elements each element separated from adjacent elements, independently supporting only a portion of a load on the base with some of the elements, while simultaneously supporting remaining portions of the load with other independent elements acting together, wherein the providing the base comprises providing a tire having side walls stretched to rims of a vehicle and providing the tire further comprises filling the tire with foam or air.
 19. A method of avoiding triggering of pressure operated land mines comprising providing a base, providing a tread on the base for contacting ground around a land mine and independently distributing pressures around the ground, wherein the providing a tread comprises providing plural independent closed cell foam rubber elements each element separated from adjacent elements, independently supporting only a portion of a load on the base with some of the elements; while simultaneously supporting remaining portions of the load with other independent elements acting together, wherein the providing the base comprises providing a cylindrical tire, filling the tire with foam or air, and wherein the providing the tread comprises providing independent radially extending elements constructed of closed cell foam.
 20. A method of avoiding triggering of pressure operated land mines comprising providing a base, providing a tread on the base for contacting ground around a land mine and independently distributing pressures around the ground, wherein the providing a tread comprises providing plural independent closed cell foam rubber elements each element separated from adjacent elements, independently supporting only a portion of a load on the base with some of the elements, while simultaneously supporting remaining portions of the load with other independent elements acting together, wherein the providing the base comprises providing continuous vehicle track and wherein the providing the tread comprises providing the independent closed cell foam elements separated from laterally and longitudinally adjacent elements.
 21. A method of avoiding triggering of pressure operated land mines comprising providing a base, providing a tread on the base for contacting ground around a land mine and independently distributing pressures around the ground, wherein the providing a tread comprises providing plural independent closed cell foam rubber elements each element separated from adjacent elements, independently supporting only a portion of a load on the base with some of the elements, while simultaneously supporting remaining portions of the load with other independent elements acting together, wherein the providing the base comprises providing a vehicle track and wherein the providing the tread comprises providing the independent closed cell foam elements separated from longitudinally adjacent elements.
 22. A method of avoiding triggering of pressure operated land mines comprising providing a base, providing a tread on the base for contacting ground around a land mine and independently distributing pressures around the ground, wherein the providing a tread comprises providing plural independent closed cell foam rubber elements each element separated from adjacent elements, independently supporting only a portion of a load on the base with some of the elements, while simultaneously supporting remaining portions of the load with other independent elements acting together, wherein the providing the base comprises providing a vehicle track and wherein the providing the tread comprises providing the independent closed cell foam elements separated from laterally adjacent elements.
 23. A method of avoiding triggering of pressure operated land mines comprising providing a base, providing a tread on the base for contacting ground around a land mine and independently distributing pressures around the ground, wherein the providing a tread comprises providing plural independent closed cell foam rubber elements each element separated from adjacent elements, independently supporting only a portion of a load on the base with some of the elements, while simultaneously supporting remaining portions of the load with other independent elements acting together, wherein the providing the base comprises providing a continuous track and wherein the providing the elements comprises providing the plural independent closed cell foam rubber elements spaced laterally and longitudinally from next adjacent elements.
 24. A method of avoiding detonating of pressure operated land mines comprising evenly distributing weight on a tread of a platform moving over a minefield among a plurality of independent soft rubber protuberances in the tread.
 25. The method of claim 24, further comprising laterally and longitudinally spacing and separating the protuberances.
 26. The method of claim 24, further comprising notching a continuous closed cell foam rubber tread for forming and separating the protuberances.
 27. A method of avoiding detonating of pressure operated land mines comprising evenly distributing weight on a tread of a platform moving over a minefield among a plurality of independent soft rubber protuberances in the tread, further comprising providing a cylindrical, continuous track, shoe or robotic foot pneumatic base and extending the pneumatic rubber protuberances from the base. 